• Title/Summary/Keyword: mechanical coupling

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Improvements of Impact strength in Glass Fiber/Polypropylene Composite by Silane Coupling Agents (실란커플링제에 의한 유리섬유/폴리프로필렌 복합재료의 충격강도 증가에 관한 연구)

  • 정광보
    • Journal of the Korean Society of Safety
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    • v.16 no.1
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    • pp.43-47
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    • 2001
  • Effect of coupling agent on the mechanical properties of PP/GF blend was investigated. The flexural modulus, Izod impact strength, elongation at yield and tensile strength were improved with using coupling agent. Mopological studies revealed that PP and GF were incompatible and addition of coupling agent was very effective to enhance the compatibility, result in mechanical properties.

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The Effect of Titanate Coupling Agents on the Electrical and Mechanical Properties of PVC-Ni Composite Systems (PVC-Ni 복합재의 전기적 ${\cdot}$ 기계적 성질에 미치는 Titanate Coupling Agent 의 영향)

  • Tak Jin Moon;Mi Kyung Lee;Sun Ho Kim
    • Journal of the Korean Chemical Society
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    • v.29 no.3
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    • pp.319-327
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    • 1985
  • The effect of titanate coupling agents on the electrical and mechanical properties of conductive poly (vinyl chloride)-nickel composite was studied as functions of filler concentration, the variation of the amount of titanate coupling agents and the type of titanate coupling agents. It was found that the electrical and mechanical properties of PVC-Ni system were improved by the treatment of titanate coupling agents, but the excessive use of titanate coupling agents influenced to give worse properties.

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A Study on Development the Dynamic Model to Misaligned Gear Coupling (I) - The Focus on Development of Dynamic Model to n Gear Coupling (정렬불량을 가진 기어 커플링의 동역학적 모델 개발에 관한 연구 (I) - 기어 커플링의 동적모델 구축을 중심으로-)

  • Kim, Byung-Ok;Kim, Yong-Chul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.6
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    • pp.857-863
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    • 2003
  • In rotating machinery, unbalance and misalignment are major concerns in vibration. Unbalance can be eliminated by balancing procedure to some degree. but little work has been done on the vibrations that occur in a misaligned rotor system. Currently, no generalized theoretical model based on a rotor system with flexible coupling is available to describe the vibrations caused by misalignment. As a part of systematic investigation on the misalignment, first of all, the study on flexible coupling with misalignment should be preceded. In this study, the geometry and reaction force and moment of a gear coupling with misalignment was investigated, also the theoretical model of a gear coupling with misalignment was presented by using the relationship between geometry and moment of gear coupling. It is expected that the proposed procedure can be applied to derive the theoretical model of other couplings.

An Experimental Study on The Coupling Path and Acoustic Modal Characteristics of a Coupled System of Passenger Compartment and Trunk (차실-트렁크 연성계의 연성경로 및 음향모드 특성에 관한 실험적 연구)

  • Lee, Jin-U;Kim, Gyu-Beom;Lee, Jang-Mu;Kim, Seok-Hyeon;Park, Dong-Cheol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.8
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    • pp.1302-1307
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    • 2001
  • This study identifies the major coupling path by examining the variation of the coupled acoustic modal frequencies and modes. A 1/2-size acryl compartment model is designed and manufactured for the measurement and analysis of coupled acoustic modes. Due to acoustic coupling, a new acoustic mode appears in a low frequency range. This coupling affects only longitudinal acoustic modes of compartment. Experimental result shows that the package tray holes contribute to the coupling much more than the back seat and hole size is an important design factor to control low frequency acoustic modes in the coupled system.

A Study on the Optimal Drive Signal Tuning of Vibratory Gyroscope (진동형 각속도계의 최적 구동신호 튜닝에 대한 연구)

  • Lee, June-Young;Jeon, Seung-Hoon;Jung, Hyoung-Kyoon;Chang, Hyun-Kee;Kim, Yong-Kweon
    • Proceedings of the KIEE Conference
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    • 2004.11a
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    • pp.40-42
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    • 2004
  • This paper describes a method to find an optimal driving condition of vibratory gyroscope. Mechanical coupling between driving and sensing mode degrades the performance of vibratory gyroscope. When the resonant frequencies of driving and sensing parts are fixed, frequency and amplitude of driving source affect mechanical coupling. Thus, they should be optimally tuned. To investigate the influence of driving source on mechanical coupling, we measured frequency response and displacement of driving and sensing mode using laser vibromenter. The measured frequency response and displacement show that the gyroscope has minimum mechanical coupling when the frequency of driving source is set to the intermediate value of driving and sensing part resonant frequency. Measurement also shows that the mechanical coupling increases abruptly at a certain driving voltage as the voltage increases.

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Development of a 3D thermohydraulic-neutronic coupling model for accident analysis in research miniature neutron source reactor (MNSR)

  • Ahmadi, M.;Rabiee, A.;Pirouzmand, A.
    • Nuclear Engineering and Technology
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    • v.51 no.7
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    • pp.1776-1783
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    • 2019
  • To accurately analyze the accidents in nuclear reactors, a thermohydraulic-neutronic coupling calculation is required to solve fluid dynamics and nuclear reactor kinetics equations in fine cells simultaneously and evaluate the local effects of neutronic and thermohydraulic parameters on each other. In the present study, a 3D thermohydraulic-neutronic coupling model is developed, validated and then applied for Isfahan MNSR (Miniature Neutron Source reactor) safety analysis. The proposed model is developed using FLUENT software and user defined functions (UDF) are applied to simulate the neutronic behavior of MNSR. The validation of the proposed model is first evaluated using 1mk reactivity insertion experiment into Isfahan MNSR core. Then, the developed coupling code is applied for a design basis accident (DBA) scenario analysis with the insertion of maximum allowed cold core reactivity of 4 mk. The results show that the proposed model is able to predict the behavior of the reactor core under normal and accident conditions with a good accuracy.

Computational Modeling of the Bearing Coupling Section of Machine Tools (공작기계 베어링 결합부의 전산 모델링)

  • Kim, Hyun-Myung;Seo, Jae-Wu;Park, Hyung-Wook
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.10
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    • pp.1050-1055
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    • 2012
  • The bearing coupling section of machine tools is the most important factor to determine their static/dynamic stiffness. To ensure the proper performance of machine tools, the static/dynamic stiffness of the rotating system has to be predicted on the design stage. Various parameters of the bearing coupling section, such as the spring element, node number and preload influence the characteristics of rotating systems. This study focuses on the prediction of the static and dynamic stiffness of the rotating system with the bearing coupling section using the finite element (FE) model. MATRIX 27 in ANSYS has been adopted to describe the bearing coupling section of machine tools because the MATRIX 27 can describe the bearing coupling section close to the real object and is applicable to various machine tools. The FE model of the bearing couple section which has the sixteen node using MATRIX 27 was constructed. Comparisons between finite element method (FEM) predictions and experimental results were performed in terms of the static and dynamic stiffness.

3-Axis Coupling Controller for High-Precision/High-Speed Contour Machining (고정밀 고속 윤곽가공을 위한 3축 연동제어기)

  • 지성철;구태훈
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.1
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    • pp.40-47
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    • 2004
  • This paper proposes a three-axis coupling controller designed to improve the contouring accuracy in machining of 3D nonlinear contours. The proposed coupling controller is based on an innovative 3D contour error model and a PID control law. The novel contour error model provides almost exact calculation of contour errors in real-time for arbitrary contours and can be integrated with any type of existing interpolator. In the proposed method, three axes of motion are coordinated by the proposed coupling controller along with a proportional controller for each axis. The proposed contour error model and coupling controller are evaluated through computer simulations. The simulation results show that the proposed 3-axis coupling controller with the new contour error model substantially can improve the contouring accuracy by order of magnitude compared with the existing uncoupled controllers in high-speed machining of nonlinear contours.

Study on Design of Coupling Bolt for Shaft in Power Plant (발전용 축계 결합용 커플링 볼트 설계에 관한 연구)

  • Jeong, HoSeung;Son, ChangWoo;Cho, JongRae;Kim, Tae Hyung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.5
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    • pp.707-713
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    • 2013
  • Coupling bolts have replaced conventional fitted bolts in applications where the operator's safety during assembly/disassembly is of concern or where the cost of process interruption is significant. Coupling bolts have been installed on rotating flange couplings in a wide range of marine and power applications worldwide. Their use has been approved by all leading international and national classification societies and regulatory bodies. A coupling bolt is a hydraulically tensioned fitted bolt that creates a stable and rigid link between coupling flanges and simplifies assembly and disassembly. We measure the bolt dimensions for reverse engineering and study the standard of assembly-load using a mechanical formula in order to localize a coupling bolt for a shaft in a power plant. We experimentally obtain the friction coefficient and confirm the condition of bolt sets through structure analysis. We show the variation of contact pressure for the shape parameter in order to consider the result when redesigning a bolt.

Shear strength prediction of PRC coupling beams with low span-to-depth ratio

  • Tian, Jianbo;Shen, Dandan;Li, Shen;Jian, Zheng;Liu, Yunhe;Ren, Wengeng
    • Earthquakes and Structures
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    • v.16 no.6
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    • pp.757-769
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    • 2019
  • The seismic performance of a coupled shear wall system is governed by the shear resistances of its coupling beams. The plate-reinforced composite (PRC) coupling beam is a newly developed form of coupling beam that exhibits high deformation and energy dissipation capacities. In this study, the shear capacity of plate-reinforced composite coupling beams was investigated. The shear strengths of PRC coupling beams with low span-to-depth ratios were calculated using a softened strut-and-tie model. In addition, a shear mechanical model and calculating method were established in combination with a multi-strip model. Furthermore, a simplified formula was proposed to calculate the shear strengths of PRC coupling beams with low span-to-depth ratios. An analytical model was proposed based on the force mechanism of the composite coupling beam and was proven to exhibit adequate accuracy when compared with the available test results. The comparative results indicated that the new shear model exhibited more reasonable assessment accuracy and higher reliability. This method included a definite mechanical model and reasonably reflected the failure mechanisms of PRC coupling beams with low span-to-depth ratios not exceeding 2.5.